Broad interests: Gene regulation in fungi, microbial and molecular ecology of symbiotic systems

Techniques used: Genetics, biochemistry, molecular biology, bioinformatics


I study Cryptococcus neoformans, a common fungus found in the soil that is normally harmless to humans. If someone with a compromised immune system inhales it, however, the fungus causes an infection in the lungs. This infection is fatal if not treated, and treatment options are currently limited.
In order to establish an infection, C. neoformans needs to import copper and iron from its surroundings. Using computer databases to search the entire genome sequence of C. neoformans and related fungi, I hope to discover molecular pathways related to metal import.


C. neoformans
Copper starvation and excess response: C. neoformans needs a way to bring copper (and other metals) into the cell whenever the surroundings are low in copper concentration. They also need a way to sequester it if it is too high (too high a concentration is toxic). We are finishing a project started by Shannon Ellis to determine which genes and pathways are affected by copper excess and starvation.
Copper regulation: The main protein that brings in copper is called Ctr4p. It is expressed in all subspecies of C. neoformans. However, the upstream DNA regions of Ctr4p in these different subspecies are not the same. We would like to figure out if the different subspecies use similar or different mechanisms to regulate the expression of this protein.
Whole genome comparisons: In collaboration with Dr. Rich Kliman at Cedar Crest College, we are in the process of sequencing the entire genome of twelve strains of C. neoformans; four taken from clinical isolates and eight isolated from the environment. We are currently attempting to map phenotypic and expression differences to known regulator regions.